EP3180535B1 - Brake device - Google Patents

Description

The invention relates to a braking device for braking a wheel, in particular a drum brake.

Braking devices for braking the wheel of a vehicle, in particular a commercial vehicle, are well known in the prior art. Drum brakes comprise a brake drum which rotates together with the wheel to be braked, and a brake lining carrier which can be covered with a brake lining and which is pressed against the brake drum when the brake is actuated. The brake lining carrier is pivotably mounted on a brake carrier and is displaced radially outward by means of an actuator unit, for example an expanding wedge, and is pressed against the inner surface of the rotating brake drum.

In particular with a view to monitoring the state of motion of the vehicle, braking devices of the type mentioned often include a sensor for recording or measuring the rotational speed of the wheel or the brake drum. The sensor can be used in particular in connection with an anti-lock braking system. A known embodiment comprises a sensor, which is fixedly mounted on the brake carrier, and a pole wheel, which rotates together with the brake drum. The sensor comprises optical sensor means for determining the rotational speed of the pole wheel relative to the sensor.

If the sensor is not arranged precisely in the intended position, interference with the measurement of the rotational speed can occur.

Usually, such a displacement of the sensor triggers an error message (so-called ABV error). In this case it is necessary to dismantle the brake drum or the wheel hub and move the sensor back into the intended position. In particular, because of the necessary dismantling of the braking device, this procedure is complex and therefore costly.

The U.S. 3,626,228 relates to a braking device for braking a wheel with a brake drum and a brake carrier, a sensor for detecting the rotational speed of the wheel being provided, which sensor is fastened to the brake carrier via a screw.

The US-2001/0052258 A1 relates to an arrangement of a sensor for detecting the rotational speed of a wheel on a hollow axle to which compressed air can be applied in order to fill the tire of a vehicle with air.

The invention is based on the object of specifying a braking device which enables a sensor, in particular an ABV sensor, to be adjusted quickly and easily.

The object is achieved according to the invention by a braking device having the features of claim 1. Preferred embodiments of the invention are specified in the dependent claims and the description below.

According to the invention, the braking device comprises a brake drum, a brake carrier for displacing a brake lining in order to press the brake lining against the brake drum, and a sensor for recording the rotational speed of the wheel. According to the invention, an adjusting element is provided which can be coupled or brought into engagement with the sensor and by means of which the sensor can be spatially displaced or adjusted. A basic idea of the invention can be seen in the sensor, in particular to couple the housing of the sensor with a mechanical adjusting element so that the sensor can be displaced by mechanical actuation or displacement of the adjusting element. It is provided in particular that the sensor can be pressed in the direction of a pole wheel by means of the actuating element or transmission element. The adjusting element preferably enables a pressure force to be transmitted to the sensor, so that the sensor can be pressed and thereby moved by a pressure force transmitted via the adjusting element. The adjusting element is preferably rigid so that a compressive force can be transmitted from the second end to the first end. The actuating element preferably has a first end which is coupled to the sensor and a second end which can be actuated manually or by a tool. The adjusting element can in particular be displaceable as a whole with no or without a substantial change in shape by a compressive force applied to the second end. The adjusting element or transmission element enables the sensor to be pushed back or displaced into its intended position without dismantling the axle device after it has moved away from the pole wheel, for example due to vibrations on the vehicle.

The adjusting element is preferably accessible from outside the brake drum. In particular, when the braking device is installed, the adjusting element can be accessible in such a way that the sensor can be spatially adjusted by means of the adjusting element.

According to the invention, the adjusting element is designed as a hollow cylinder or sleeve. The adjusting element takes up a cable element of the sensor. The cable element of the sensor preferably runs within the actuating element. It is particularly preferred that the cable element is led out of the braking device or the brake drum together with the adjusting element. The cable element can in particular be an electrically conductive cable or a cable wire.

According to a further preferred embodiment it is provided that the adjusting element forms an integral part of a cable sleeve. The particular electrical cable element, for example for connecting the sensor to a signal processing unit, runs inside the cable sleeve, which is rigidly designed so that compressive forces can be transmitted from one end to the end adjacent to the sensor. Thus, the cable formed by the cable sleeve and the cable element extending therein can be pressed at its end opposite the sensor and the sensor can thus be displaced. The adjusting element can consequently also be referred to as a dimensionally stable or rigid cable sleeve that transmits pressure forces.

Another preferred embodiment of the invention provides that the adjusting element has a length which corresponds to at least a distance of the sensor from an outside of the braking device. The adjusting element preferably runs between the sensor and an outside of the braking device. In this way, the adjusting element is accessible even when the braking device is installed.

It is particularly preferred that the adjusting element protrudes from an interior of the brake drum. Preferably, the actuating element runs in sections through an interior of the braking device or the brake drum and out of the interior of the braking device or the brake drum.

In a further preferred embodiment, the adjusting element is mounted in an opening of a closure plate of the braking device and / or protrudes through it. The closure plate can in particular be an element which delimits an interior space of the brake drum and protects it from contamination, for example. The closure plate is preferably arranged at an open, axial end of the brake drum. This can be a stationary element which can be formed integrally with the brake carrier. The brake drum can be designed to be rotatable relative to the closure plate.

The adjusting element can be formed from metal and / or plastic, for example. It is crucial that the adjusting element has a hardness or rigidity that allows the sensor to be displaced over the adjusting element. In contrast to conventional cable sleeves, the adjusting element is therefore not flexible at will, but is at least largely dimensionally stable. A hard plastic is particularly preferred as the plastic.

Good actuation of the actuating element can be achieved if the actuating element has a longitudinal axis which runs along a longitudinal axis of the sensor. The adjusting element is therefore preferably aligned with the longitudinal axis of the sensor. The essentially elongated and / or rotationally symmetrical adjusting element according to the invention preferably runs coaxially to the longitudinal axis of the sensor, the longitudinal axis of the sensor in the case of an optical sensor running, for example, in the direction of the beam path of the emitted beams.

It is preferred that the sensor can be inserted axially into a sensor holder. The invention then enables the sensor to be pushed or shifted into the sensor holder by means of the adjusting element, if the sensor has partially detached itself from the sensor holder or has shifted within it.

It is particularly preferred that the sensor can be adjusted in an axial direction, that is to say in the direction of the longitudinal axis of the sensor, by means of the adjusting element. In this way, no force deflection is required. The sensor can be pushed into or pushed back into the sensor holder in a particularly simple manner by applying pressure in the axial direction on the adjusting element.

It is particularly advantageous here if the adjusting element can be displaced along the axial direction and / or along the direction of the longitudinal axis of the sensor.

It is useful if the adjusting element, preferably in the area of its second end and in particular in the area of a part protruding from the closure plate, has indicator means, such as a marking, by means of which the position of the adjusting element can be recognized in the installed state. It is thus possible to visually indicate whether the sensor or the actuating element is in the fault position or in the operating position.

The invention is described further below with reference to a preferred embodiment, which is shown schematically in the accompanying figure.

Fig. 1

zeigt eine Querschnittansicht einer erfindungsgemäßen Bremsvorrichtung.

The only

Fig. 1

shows a cross-sectional view of a braking device according to the invention.

The braking device 10 comprises a brake drum 20 which is rotatably mounted on an axle element 12. The axle element 12 extends along a longitudinal axis, which is identified in the figure by the reference number 14. The axle element 12 can, for example, be a stationary, that is to say non-rotating, axle of a vehicle, in particular a utility vehicle.

For the rotating mounting of the brake drum 20 relative to the axle element 12, bearing devices 22, for example roller bearings, are provided. A wheel hub 26 is rotatably mounted on the bearing devices 22 relative to the axle element 12. The brake drum 20 is firmly connected to the wheel hub 26, so that it can be rotated together with the wheel hub 26 about the axle element 12. Fastening bolts 28 are provided for the non-rotatable connection of wheel hub 26 and brake drum 20. Instead of the bolts 28, however, other fastening devices can also be provided.

The brake drum 20 is drum-shaped and comprises a drum ring 21, which extends in the axial direction and in the circumferential direction around the axle element 12 and surrounds or delimits a drum interior 24.

In the interior of the drum 24, that is to say inside the brake drum 20, a brake carrier 30 is arranged, which is firmly connected to the axle element 12. The brake carrier 30 carries a brake lining carrier 32, which is not visible in the sectional view and is only indicated schematically. The brake lining carrier 32 is covered on its radially outer surface with brake linings 34, likewise only indicated schematically, which press against an inner peripheral surface of the brake drum 20 when the braking device 10 is actuated. An actuating device 36, for example an expanding wedge unit, is provided for the radial displacement of the brake lining carrier 32. The actuating device 36 can usually be operated hydraulically and can have a hydraulic cylinder for this purpose.

The drum interior 24 is closed, in particular to protect against contamination, by a closure plate 40, which is arranged on the axle element 12 in a non-rotating manner. The closure plate 40 is located on an axial end face of the drum interior 24, which in the assembled state of the braking device 10 faces the center of the vehicle. The closure plate 14 can be viewed as part of the brake carrier 30 and can be designed integrally with it, for example as a cast part. The closure plate 40 is located, in particular, at an open end of the brake drum 20.

A pole wheel 58 is arranged on the rotating components of the braking device 10, in particular on the wheel hub 26. The pole wheel 58 is mounted rotatably relative to the axle element 12 and rotates together with the brake drum 20 or the wheel hub 26. In a basically known manner, it comprises a plurality of webs and openings in the circumferential direction, which by means of a sensor 50, in particular an optical sensor, are detectable. The sensor 50 is for this purpose arranged in a fixed position relative to the axle element 12 and fastened, for example, to the brake carrier 30. When the brake drum 20 rotates about the axle element 12, the sensor 50 can determine the speed of rotation in a basically known manner by measuring the speed of the bars and / or openings of the pole wheel 58 passing by the sensor 50. The sensor 50 comprises a sensor housing 52 that is received in a sensor holder 54. A longitudinal axis or central axis of the sensor 50, which is referred to as the sensor longitudinal axis 56, runs in the axial direction of the axle element 12, in particular parallel to the longitudinal axis 14. The sensor 50 can be inserted into the sensor holder 54 along the sensor longitudinal axis 56 and pressed down to a stop. In the Fig. 1 The position of the sensor 50 shown is referred to as the operating position. In this position it is possible to measure the rotational speed of the wheel or of the brake drum 20 about the axle element 12.

By unintentional displacement of the sensor 50 away from the pole wheel 58, ie in the Fig. 1 to the right, a malfunction can occur so that a measurement of the rotational speed is no longer possible. This position is called the fault position. To move the sensor 50 from its fault position to the operating position, an adjusting element 60 is provided, which is connected to or can be brought into engagement with the sensor 50, in particular the sensor housing 52. The actuating element 60 extends out of the drum interior 24 from the sensor 50 arranged in the drum interior 24. It extends through the closure plate 40, in which an opening 42 is formed for this purpose. The adjusting element 60 is sleeve-shaped or rod-shaped and in particular an elongated element which extends in the axial direction of the braking device 10, preferably parallel to the longitudinal axis 14. An electrical or optical cable element 62 preferably runs in the adjusting element 40, so that the adjusting element 60 forms a covering for the cable element 62. The cable element 62 can protrude from the adjusting element 60 at the end opposite the sensor 50. So that the sensor 50 is pressed towards the pole wheel 58 via the adjusting element 60 The adjusting element 60 is designed to be stiff or rigid and preferably runs along a straight line, in particular coaxially to the longitudinal axis 56 of the sensor The actuating element preferably has a length which is greater than the distance between the sensor 50 and an axial delimitation of the drum interior 54, in particular the closure plate 40.

It is particularly preferred if the adjusting element 60 protrudes through the closing plate 40 and protrudes at least 5-15 mm from it. This ensures reliable actuation and, if necessary, visual inspection from outside the braking device 10 delimited by the brake drum 20 and / or the closure plate 40. The adjusting element 60 can also be referred to as a stiff or rigid cable sleeve or additional sleeve or as a dimensionally stable or additional cable reinforcement . With the additional sleeve or cable reinforcement, an error (ABV error) caused by a displacement of the sensor 50 can be eliminated without dismantling any add-on parts.

List of reference symbols

10

Braking device

12th

Axillary element

14th

Longitudinal axis

20th

Brake drum

21st

Drum ring

22nd

Storage facility

24

Drum interior

26th

wheel hub

28

Fastening bolts

30th

Brake carrier

32

Brake lining carrier

34

Brake pad

36

Actuator

40

Locking plate

42

opening

50

sensor

52

Sensor housing

54

Sensor bracket

56

Longitudinal sensor axis

58

Pole wheel

60

Control element

62

Cable element

Claims (12)

1. A brake device for braking a wheel, having
   a brake drum (20),
   a brake carrier (30) for shifting a brake lining (34) with respect to the brake drum (20), and
   a sensor (50) for detecting a rotational speed of the wheel,
   wherein an adjustment element (60) is provided which can be engaged with the sensor (50) and by means of which the sensor (50) can be shifted spatially, characterized in that
   the adjustment element (60) is embodied in the form of a sleeve and accommodates a cable element (62) of the sensor (50),
   wherein the rotationally symmetrical adjusting element runs coaxially to a sensor longitudinal axis.
2. The brake device as claimed in claim 1,
   wherein the adjustment element (60) is configured to transmit a pressure force to the sensor (50), and wherein the adjustment element (60) is preferably embodied in a rigid fashion.
3. The brake device as claimed in one of the preceding claims,
   wherein the adjustment element (60) forms an integral part of a cable sleeve.
4. The brake device as claimed in one of the preceding claims,
   wherein the adjustment element (60) has a length which corresponds to at least a distance of the sensor (50) from an outer side of the brake device (10).
5. The brake device as claimed in one of the preceding claims,
   wherein the adjustment element (60) is accessible from outside the brake drum (20).
6. The brake device as claimed in one of the preceding claims,
   wherein the adjustment element (60) projects out of an interior space of the brake drum (20).
7. The brake device as claimed in one of the preceding claims,
   wherein the adjustment element (60) projects through, or is mounted in, an opening (42) in a closure plate (40) of the brake device (10).
8. The brake device as claimed in one of the preceding claims,
   wherein the adjustment element (60) is formed from metal and/or plastic.
9. The brake device as claimed in one of the preceding claims,
   wherein the adjustment element (60) has a longitudinal axis which runs along a sensor longitudinal axis (56).
10. The brake device as claimed in one of the preceding claims,
    wherein the sensor (50) can be plugged axially into a sensor mount (54).
11. The brake device as claimed in one of the preceding claims,
    wherein the sensor (50) can be adjusted in an axial direction by means of the adjustment element (60).
12. The brake device as claimed in one of the preceding claims,
    wherein the adjustment element (60) has indicator means, preferably in the region of its end and, in particular, in the region of a part projecting out of the closure plate.

Images